For the Birds: Mystery disease killing birds in U.S.

Photo by Chris Bosak An American Goldfinch with Avian Conjunctivitis visits a birdfeeder in Danbury, Conn., April 2016. A different disease is killing birds in the U.S. this summer.

Something is killing birds in unusually large numbers.

An as-of-yet undetermined disease has taken a heavy toll on birds such as robins, blue jays and grackles in about a dozen Mid-Atlantic and Midwest states. The die-off started in May and, while it hasn’t reached New England yet (as far as we know), officials at conservation organizations are encouraging people to take precautions to protect birds. Among the precautions: Stop feeding birds (or at least wash all feeders with a 10 percent bleach solution) and discontinue the use of birdbaths temporarily.

Disorientation, imbalance, lethargy and encrusted or cloudy eyes are among the symptoms of the birds afflicted with the disease. Young birds appear to have been disproportionately impacted. Researchers have confirmed that this differs from the avian conjunctivitis that has plagued house finches and goldfinches for many years. They have also ruled out many other potential causes, such as bacteria, viruses and parasites that commonly afflict birds.

It’s important to know what is not causing the die-off, of course, but finding out what is causing the event is even more significant. Determining that is still a work in progress.

One theory, which has been applauded by some and discounted by others, is that the die-off is related to the 17-year Brood X periodical cicada emergence. The geography of the die-off and emergence appears to align, and the theory suggests that the cicadas, which have been underground for 17 years, have soaked up pesticides, herbicides and whatever other nasty stuff we’ve been using to control insects and grow our grass and crops. It seems to make sense, but as I’ve mentioned, many researchers do not think the link is plausible.

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